Help with Super Chromega C Dichroic enlarger

subtlelikeatrex · May 10, 2025

Hi folks! I'm new here but I've been making photographs for most of my life.
I was recently gifted an Omega enlarger...the Super Chromega C Dichroic and I need some help with it.

My main issue is with the focusing operation. I have a 35mm negative in the proper negative carrier but in order for the image to come into focus, or rather...anywhere near in-focus, I have to compress the bellows completely. Even with the bellows compressed all the way up, the image is still not in accurate focus. I've never owned an enlarger but have used them in school and have never experienced this issue...where the bellows need to be fully squashed to get the image in-focus. Is there anyone who has experience with this enlarger who can tell me what I'm doing wrong? Was I maybe given the wrong lens with it? Could that be the problem?

My second question: There are four levers or dials on the right side of the enlarger. Aside from the two obvious ones (one raises and lowers the lamp house and one is the focusing knob) I cannot tell what the other two levers are for. There is a grey lever on the side of the lamp house and a black dial on the bracket that holds the lamp house to the tower. (The black dial only makes about 1/8 of a turn.) I cannot tell what the function of either of these is. Does one of these have something to do with my focusing problem? What do they do? I though the black one on the bracket might lock the height of the lamp house but it doesn't seem to do anything.

Lastly, the head of the unit, or the lamp house, wobbles ever so slightly on its mount making it so that the lamp house is not perfectly level. It seems like it may be loose or not attached properly somehow. It doesn't seem like something that should have some wiggle or play in it for such a precise instrument. Is this something I can tighten myself or is this normal?

I will probably mainly be using it for black & white enlargements. Thank you for reading. I would appreciate any advice I can get. I already ordered a paper copy of the manual from KHB Photografix but I'm in Hawaii so it may take a while to get here

Thanks!

mwdake · May 10, 2025

I don’t own a Chromega C, I have a different Omega color head.
But…
Looking at the position of the levers I think the large grey one is to change the light source from filtered to white light and the smaller black one is the column lock to prevent the head moving once you have it set.

For the lens focus problem. That lens is a wide angle lens for 35mm but not sure if that is the problem. Typically a 50mm lens is used for 35mm negatives. It’s possible you need a different mount for the lens.

MattKing · May 10, 2025

Welcome to Photrio!
I think that is an Omega C67 enlarger with the Super Chromega C Dichroic head mounted, and a 38mm lens .
A 38mm lens would normally be used with a smaller film format than 135 film, and with one of the relatively few recessed lens mounts designed for it.
Here is the KHB Photografix page that applies: http://www.khbphotografix.com/omega/Enlargers/C67.htm
There is a reasonable chance that your bellows compression issue is due to the lens being installed on a lens mount designed for a longer lens - something like a 50mm focal length lens better suited for 135 film.

subtlelikeatrex · May 10, 2025

mwdake said:
I don’t own a Chromega C, I have a different Omega color head.
But…
Looking at the position of the levers I think the large grey one is to change the light source from filtered to white light and the smaller black one is the column lock to prevent the head moving once you have it set.

For the lens focus problem. That lens is a wide angle lens for 35mm but not sure if that is the problem. Typically a 50mm lens is used for 35mm negatives. It’s possible you need a different mount for the lens.

You are right about the grey lever and the black dial. I adjusted the color filter sliders, moved the lever and…bam…colored light went to white.
I also just found a listing for a used Chromega C where it mentions that its height lock lever is broken. That must be the case with mine too.

I believe you’re correct about the lens being my focus issue as well. I guess I need a new lens.
Thanks for the help!

subtlelikeatrex · May 10, 2025

MattKing said:
Welcome to Photrio!
I think that is an Omega C67 enlarger with the Super Chromega C Dichroic head mounted, and a 38mm lens .
A 38mm lens would normally be used with a smaller film format than 135 film, and with one of the relatively few recessed lens mounts designed for it.
Here is the KHB Photografix page that applies: http://www.khbphotografix.com/omega/Enlargers/C67.htm
There is a reasonable chance that your bellows compression issue is due to the lens being installed on a lens mount designed for a longer lens - something like a 50mm focal length lens better suited for 135 film.

Ok thanks! When you say “lens mount” is that the same as the lens board? Sorry…I’m just learning about enlargers for the first time. Would this lens mount that I have be appropriate for a 50mm focal length lens (as long as it fits the same 39mm thread of the retainer ring)? Would a 50mm lens work for 120 film negatives as well? I don’t have a negative carrier for 6x4.5 but I plan to get one since I also shoot medium format.

Thanks so much for the advice!
José

MattKing · May 11, 2025

subtlelikeatrex said:
Ok thanks! When you say “lens mount” is that the same as the lens board? Sorry…I’m just learning about enlargers for the first time. Would this lens mount that I have be appropriate for a 50mm focal length lens (as long as it fits the same 39mm thread of the retainer ring)? Would a 50mm lens work for 120 film negatives as well? I don’t have a negative carrier for 6x4.5 but I plan to get one since I also shoot medium format.

Thanks so much for the advice!
José

Some enlargers use flat pieces of metal to mount lenses - which can reasonably be referred to as lens boards.
Other enlargers use more complex shapes of (usually) metal, so they are usually not referred to as lens boards, but instead as lens mounts.
And other enlargers use a combination of various shapes of metal mounts combined with replaceable plates that work with them and are, not surprisingly, referred to as lens plates.
That KHB site I linked to shows the nomenclature - lens disk - that applies to your enlarger. The recessed lens mounts are essentially accessories that permit use of unusually short lenses, like the 38mm lens you have.
A 50mm lens will have the coverage and give you the magnification best suited to 135 film.
For larger, medium format negatives, you will generally want longer lenses.
The rough guide being:
- a 75mm lens for 6x4.5 (although an 80mm lens would work fine)
- an 80mm lens for 6x6
- a 90mm lens for 6x7
- a 105mm lens for 6x9
You can use longer lenses than the focal lengths recommended for each format, but that will limit somewhat the maximum size of your prints, and sometimes result in using a lens outside its optimum range of magnification. In addition, longer lenses often have smaller maximum apertures, so the image is dimmer on the baseboard when composing or focusing.
80mm and 50mm are the focal lengths that are easiest to find. Some of the 80mm lens are specifically designed to give high quality results with film formats from 6x4.5 right through 6x7, so those lenses are quite desirable.
To give you a small taste of some of the plethora of lenses out there, it is useful to look at this table relating to the Omega D5 which also comes from KHB's site: http://www.khbphotografix.com/omega/LensMountD5.htm
Obviously, the lens mounts referenced therein are not the ones for your enlarger, but the list of lenses and associated mounting threads is helpful.
By the way, "KHB"is a reference to the initials of the owner, Kevin Brown. Mr. Brown is in my experience very helpful, particularly considering you have already purchased from them .
I see you are based in Hawaii. One of our Moderators, @David A. Goldfarb , is based in Hawaii. He may see this reference to his name, and be able to assist you with resources easy to access from Hawaii.

subtlelikeatrex · May 11, 2025

MattKing said:
Some enlargers use flat pieces of metal to mount lenses - which can reasonably be referred to as lens boards.
Other enlargers use more complex shapes of (usually) metal, so they are usually not referred to as lens boards, but instead as lens mounts.
And other enlargers use a combination of various shapes of metal mounts combined with replaceable plates that work with them and are, not surprisingly, referred to as lens plates.
That KHB site I linked to shows the nomenclature - lens disk - that applies to your enlarger. The recessed lens mounts are essentially accessories that permit use of unusually short lenses, like the 38mm lens you have.
A 50mm lens will have the coverage and give you the magnification best suited to 135 film.
For larger, medium format negatives, you will generally want longer lenses.
The rough guide being:
- a 75mm lens for 6x4.5 (although an 80mm lens would work fine)
- an 80mm lens for 6x6
- a 90mm lens for 6x7
- a 105mm lens for 6x9
You can use longer lenses than the focal lengths recommended for each format, but that will limit somewhat the maximum size of your prints, and sometimes result in using a lens outside its optimum range of magnification. In addition, longer lenses often have smaller maximum apertures, so the image is dimmer on the baseboard when composing or focusing.
80mm and 50mm are the focal lengths that are easiest to find. Some of the 80mm lens are specifically designed to give high quality results with film formats from 6x4.5 right through 6x7, so those lenses are quite desirable.
To give you a small taste of some of the plethora of lenses out there, it is useful to look at this table relating to the Omega D5 which also comes from KHB's site: http://www.khbphotografix.com/omega/LensMountD5.htm
Obviously, the lens mounts referenced therein are not the ones for your enlarger, but the list of lenses and associated mounting threads is helpful.
By the way, "KHB"is a reference to the initials of the owner, Kevin Brown. Mr. Brown is in my experience very helpful, particularly considering you have already purchased from them .
I see you are based in Hawaii. One of our Moderators, @David A. Goldfarb , is based in Hawaii. He may see this reference to his name, and be able to assist you with resources easy to access from Hawaii.

Well, Matt…you have provided me with way more information than I ever expected to glean from this thread. Thank you so much for your kind help and your time! I sincerely appreciate it!
It seems that my 38mm lens will not be very useful to me. I will do some research and seek out a 50mm and, likely, an 80mm enlarger lens. If I’m understanding correctly, I may need to find a new lens mount or lens disk that will hold these lenses in the right position (i.e. not a recessed lens mount?)

José

MattKing · May 11, 2025

Glad to help!
Can you show us a better image - possibly from the side - of the disk/mount on the lens you have?
It may be that it is not a recessed mount, and therefor appropriate for a 50mm or 80mm lens - assuming the correct mounting thread.
Your difficulty with the 38mm lens and bellows compression is a hint that it is not a recessed mount, because that is one of the issues that recessed mounts are designed to deal with.
Don't discard the 38mm lens, because you never know when the attributes of all the excellent 1/2 frame 35mm cameras out there may start to interest you - that being the film format that a 38mm lens would be perfect for.
One caution: if you are like me and use multiple formats, and therefore multiple enlarging lenses, you will probably find that you will want to have each lens accompanied by its own appropriate board/mount/disk.
Generally, you can use one such board/mount/disk and just keep moving lenses off and on to it, but that can get a bit tiresome.

subtlelikeatrex · May 11, 2025

MattKing said:
Glad to help!
Can you show us a better image - possibly from the side - of the disk/mount on the lens you have?
It may be that it is not a recessed mount, and therefor appropriate for a 50mm or 80mm lens - assuming the correct mounting thread.
Your difficulty with the 38mm lens and bellows compression is a hint that it is not a recessed mount, because that is one of the issues that recessed mounts are designed to deal with.
Don't discard the 38mm lens, because you never know when the attributes of all the excellent 1/2 frame 35mm cameras out there may start to interest you - that being the film format that a 38mm lens would be perfect for.
One caution: if you are like me and use multiple formats, and therefore multiple enlarging lenses, you will probably find that you will want to have each lens accompanied by its own appropriate board/mount/disk.
Generally, you can use one such board/mount/disk and just keep moving lenses off and on to it, but that can get a bit tiresome.

I did just meet a guy here who was using a 35mm half frame camera. I was intrigued for sure. I'll hang on to this lens.
Here's a couple photos of the mount. I see now that it does have the part number engraved into it which is listed on the KHB site. I'm guessing since it is flat that it is not considered the recessed mount.

Ian C · May 11, 2025

The 421-017 flat lens mount as shown in post #9 is the same as used on the B66 enlarger for 39mm Leica mount lenses.

The Fujinon EP 1:4.5 38 mm enlarging lens (39 mm Leica mounting thread) is intended to enlarge negatives up to 24 x 24 mm. To make an 8” x 10” borderless print from that size negative (or that size portion of any negative) would require a projection of about 260 x 260 mm, magnification 10.8X. The focal length is 38 mm and the flange distance of the lens is given by Fuji as 32.9 mm.

The data and dimensioned sectional drawing of this lens is given in the following Fuji catalog:

https://www.pacificrimcamera.com/rl/00886/00886.pdf

10.8X magnification would place the mounting flange of the lens (flat surface behind the mounting thread) 41.5 mm from the bottom surface of the negative to obtain focus. This would require a recessed lens mount. The KHB Photographix site lists only two recessed mounts. Both have hole sizes less than 39 mm. It’s likely that there simply isn’t enough room in the lens stage for a recessed mount for a lens with a 39 mm diameter mount thread because the hole in the lens stage is too small. If so, then this lens isn’t usable on the Omega C67.

421-006 Recessed Lens Mount - 32.5mm hole

421-007 Recessed Lens Mount - 25mm hole

http://www.khbphotografix.com/omega/Enlargers/C67.htm

You can take a measurement of your enlarger to determine what is the closest distance A from the bottom of the negative to the bottom surface of the lens-mount stage with the bellows closed—but not compressed.

The recessed lens mount must allow the lens flange placed at 41 mm or somewhat less to attain focus at 10.8X magnification.

If you want the ability to make an 11” x 14” print, the required magnification is 15X and the negative-to-flange distance is at most 40.5 mm.

For a 16” x 20” print (21.2X), you’d need the lens flange no more than 39.8 mm from the negative. In this case, the lens would have to be recessed at least A – 39.8 mm (assuming that A greater than 39.8 mm).

MattKing · May 11, 2025

Ian is probably right - your 38mm lens may simply be too (physically) large to fit into the recessed mounts available for your enlarger.
You would have to find one of those mounts to see whether one could be modified by someone with machine shop capabilities to fit the lens you have - probably not. Kevin Brown would be a good person to ask.
By the way - the photos you just shared are great - far clearer than many we see from people asking for this sort of advice!

subtlelikeatrex · May 12, 2025

Ian C said:
The 421-017 flat lens mount as shown in post #9 is the same as used on the B66 enlarger for 39mm Leica mount lenses.

The Fujinon EP 1:4.5 38 mm enlarging lens (39 mm Leica mounting thread) is intended to enlarge negatives up to 24 x 24 mm. To make an 8” x 10” borderless print from that size negative (or that size portion of any negative) would require a projection of about 260 x 260 mm, magnification 10.8X. The focal length is 38 mm and the flange distance of the lens is given by Fuji as 32.9 mm.

The data and dimensioned sectional drawing of this lens is given in the following Fuji catalog:

https://www.pacificrimcamera.com/rl/00886/00886.pdf

10.8X magnification would place the mounting flange of the lens (flat surface behind the mounting thread) 41.5 mm from the bottom surface of the negative to obtain focus. This would require a recessed lens mount. The KHB Photographix site lists only two recessed mounts. Both have hole sizes less than 39 mm. It’s likely that there simply isn’t enough room in the lens stage for a recessed mount for a lens with a 39 mm diameter mount thread because the hole in the lens stage is too small. If so, then this lens isn’t usable on the Omega C67.

421-006 Recessed Lens Mount - 32.5mm hole

421-007 Recessed Lens Mount - 25mm hole

http://www.khbphotografix.com/omega/Enlargers/C67.htm

You can take a measurement of your enlarger to determine what is the closest distance A from the bottom of the negative to the bottom surface of the lens-mount stage with the bellows closed—but not compressed.

The recessed lens mount must allow the lens flange placed at 41 mm or somewhat less to attain focus at 10.8X magnification.

If you want the ability to make an 11” x 14” print, the required magnification is 15X and the negative-to-flange distance is at most 40.5 mm.

For a 16” x 20” print (21.2X), you’d need the lens flange no more than 39.8 mm from the negative. In this case, the lens would have to be recessed at least A – 39.8 mm (assuming that A greater than 39.8 mm).

Thank you for the info Ian! I am mainly interested in making prints from 135 and 120 film negatives. I had my fill of making 8x10s back in school so I plan to print both smaller and larger…likely 5x7 and 11x14. Maybe even 16x20. Just very excited to print again.

DREW WILEY · Jun 19, 2025

It's been 50 years since I had one of those enlargers, so my memory might be a bit rusty. I pretty much covered all the bases, 35mm to 6x9, with only two focal length lenses, 50mm and 105mm. No recessed cone was necessary. It's difficult to maintain
precise focus unless film flatness is retained, which requires some kind of tight sandwiched glass negative carrier. I improvised by using Anti-Newton glass Gepe slide mounts, both 35mm and 6x7. These can still sometimes be found inexpensively, and can be reused for different negatives.

Now I have far more serious enlargers with all kinds of precision accessories. But you should be able to do just fine with the one you already have once you get everything properly leveled and aligned, along with appropriate lenses.

Help with Super Chromega C Dichroic enlarger

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